1895551 - Setting Null on ElementInternals attributes does not remove attribute

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[Eitan Isaacson [:eeejay]]

Given:

<custom-slider></custom-slider>
<script>
customElements.define(`custom-slider`,
    class extends HTMLElement {
      constructor() {
        super();
        this._internals = this.attachInternals();
        this._internals.role = slider;
        this._internals.ariaValueNow = "5";
        this._internals.ariaValueMin = "1";
        this._internals.ariaValueMax = "10";
        this._internals.ariaValueText = null;
      }
    }
  );
</script>

The expected value would be "5", but it is "". This is because ElementInternals does not treat null values correctly and considers the ariaValueText attribute to be set.

Comment 1

[Eitan Isaacson [:eeejay]]

While we could fix this in a11y by distinguishing between a null and empty string attribute, I would argue that the correct remedy is that the attribute should be unset in the internals when null is passed. This is the same behavior in Element.

Comment 2

[Eitan Isaacson [:eeejay]]

Attachment: Bug 1895551 - Remove aria attribute from ElementInternals when set to null. r?jamie,#dom-core-reviewers

Comment 3

[James Teh [:Jamie]]

FWIW, we originally had the same bug in Element, bug 1853209. That was definitely contrary to the spec.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/820577191451
Remove aria attribute from ElementInternals when set to null. r=Jamie,dom-core,edgar

Comment 5

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/820577191451